Method for manufacturing diamond substrate

Abstract

The present invention provides a method for manufacturing a diamond substrate, including: a first step of preparing patterned diamond on a foundation surface, a second step of removing a foreign substance adhered on a wall of the patterned diamond prepared in the first step, and a third step of growing diamond from the patterned diamond prepared in the first step to form the diamond in a pattern gap of the patterned diamond prepared in the first step. There can be provided a method for manufacturing a diamond substrate with few dislocation defects, in which generation of abnormal growth particles are suppressed.

The invention claimed is: 
     
       1. A method for manufacturing a diamond substrate, comprising:
 a first step of preparing patterned diamond by growing diamond on a surface of a foundation, the surface being composed of a different material other than diamond, and processing the grown diamond to have a patterned shape, 
 wherein a bottom portion of a pattern gap of the patterned diamond is composed of a different material or at least a part of the bottom portion of the pattern gap is pierced through, 
 a second step of removing a foreign substance other than diamond adhered on a side wall of a pattern of the patterned diamond prepared in the first step, and 
 a third step of growing diamond from the patterned diamond prepared in the first step to form the diamond in the pattern gap of the patterned diamond prepared in the first step. 
 
     
     
       2. The method for manufacturing a diamond substrate according to  claim 1 , wherein the foreign substance adhered on the wall of the patterned diamond is removed by using CF 4  plasma in the second step. 
     
     
       3. The method for manufacturing a diamond substrate according to  claim 1 , wherein the patterned diamond is prepared in the first step with a ratio D/W of a depth D to a width W of the pattern gap being 0.1 or more. 
     
     
       4. The method for manufacturing a diamond substrate according to  claim 1 , wherein the patterned diamond is prepared in the first step with at least a part of a bottom portion of the pattern gap being prepared below the foundation surface. 
     
     
       5. The method for manufacturing a diamond substrate according to  claim 1 , wherein the diamond is grown by using a chemical vapor deposition method in the third step. 
     
     
       6. The method for manufacturing a diamond substrate according to  claim 1 , wherein a void is formed in the diamond grown in the third step. 
     
     
       7. The method for manufacturing a diamond substrate according to  claim 5 , wherein a void is formed in the diamond grown in the third step.